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VG2 JUP LECP CALIBRATED RESAMPLED SECTORED 15MIN V1.1 (PDS)

NSSDCA ID: PSFP-00551

Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1979-07-02 to 1979-08-03

Description

This description was generated automatically using input from the Planetary Data System.

Data Set Description ==================== Version 1.1 ----------This version 1.1 data set replaces the version 1.0 data set (DATA_SET_ID = VG2-J-LECP-4-15MIN) previously archived with the PDS. Data records from the version 1.0 data set provided data for each of 8 sectors, plus the average for all sectors in a separate record for each channel. This resulted in 9 repeated times per channel. Data records for the version 1.1 data set provide all data for a given channel and time period (8 sectors, plus the average for all sectors) in a single record. Other changes to this version include upgrading of the associated labels and templates to PDS version 3.4 compliance, modification of the time formats and flag values. Data Set Description -------------------This data set consists of resampled data from the Low Energy Charged Particle (LECP) experiment on Voyager 2 while the spacecraft was in the vicinity of Jupiter. This instrument measures the intensities of in-situ charged particles (>26 keV electrons and >30 keV ions) with various levels of discrimination based on energy, mass species, and angular arrival direction. A subset of almost 100 LECP channels are included with this data set. The LECP data are globally calibrated to the extent possible (see below) and they are time averaged to about 15 minute time intervals with the exact beginning and ending times for those intervals matching the LECP instrumental cycle periods (the angular scanning periods). The LECP instrument has a rotating head for obtaining angular anisotropy measurements of the medium energy charged particles that it measures. The cycle time for the rotation is variable, but during encounters it is always faster than 15 minutes. Thus, the full angular anisotropy information is preserved with this data. The data is in the form of 'rate' data which has not been converted to the usual physical units. The reason is that such a conversion would depend on uncertain determinations such as the mass species of the particles and the level of background. Both mass species and background are generally determined from context during the study of particular regions. To convert 'rate' to 'intensity' for a particular channel one performs the following tasks: 1) Decide on the level of background contamination and subtract that off the given rate level. Background is to be determined from context and from making use of sector 8 rates (sector 8 has a 2 mm Al shield covering it). 2) Divide the background corrected rate by the channel geometric factor and by the energy bandpass of the channel. The geometric factor is found in entry 'CHANNEL_GEOMETRIC_FACTOR' as associated with each channel 'CHANNEL_ID'. To determine the energy bandpass, one must judge the mass species of the of the detected particles (for ions but not for electrons). The energy band passes are given in entries 'MINIMUM_INSTRUMENT_PARAMETER' and 'MAXIMUM_INSTRUMENT_PARAMETER' in table 'FPLECPENERGY', and are given in the form 'energy/nucleon'. For channels that begin their names with the designations 'CH' these bandpasses can be used on mass species that are accepted into that channel (see entries 'MINIMUM_INSTRUMENT_PARAMETER' AND 'MAXIMUM_INSTRUMENT_PARAMETER' in table 'FPLECPCHANZ', which give the minimum and maximum 'Z' value accepted -- these entries are blank for electron channels). For other channels the given bandpass refers only to the lowest 'Z' value accepted. The and passes for other 'Z' values are not all known, but some are given in the literature (e.g. [KRIMIGISETAL1979A]). The final product of these instructions will be the particle intensity with the units: counts/(cm^2 str sec keV). Parameters ========== Electron Rate ------------Sampling Parameter Name : TIME Data Set Parameter Name : ELECTRON RATE Sampling Parameter Resolution : 15.000000 Sampling Parameter Interval : 15.000000 Data Set Parameter Unit : COUNTS/SECOND Noise Level : 0.000000 Sampling Parameter Unit : MINUTE A measured parameter equaling the number of electrons hitting a particle detector per specified accumulation interval. The counted electrons may or may not be discriminated as to their energies (e.g. greater than E1, or between E1 and E2). Ion Rate -------Sampling Parameter Name : TIME Data Set Parameter Name : ION RATE Sampling Parameter Resolution : 15.000000 Sampling Parameter Interval : 15.000000 Data Set Parameter Unit : COUNTS/SECOND Noise Level : 0.000000 Sampling Parameter Unit : MINUTE A measured parameter equaling the number of ions striking a particle detector per specified accumulation interval. The counted ions may or may not be discriminated as to their energies (e.g. energy/nucleon or energy/charge between E1 and E2 or greater than E1) and/or as to their ion composition (atomic number Z or mass number greater than Z1 or M1, or between Z1 and z2 or M1 and M2). Source Instrument Parameters ============================ Instrument Host ID : VG2 Data Set Parameter Name : ION RATE Instrument Parameter Name : ION RATE Important Instrument Parameters : 1 Instrument Host ID : VG2 Data Set Parameter Name : ELECTRON RATE Instrument Parameter Name : ELECTRON RATE Important Instrument Parameters : 1 Processing ========== Processing Level Id : 4 Software Flag : Y Processing Start Time : 1988-08-01 Processing History -----------------Source Data Set ID : VG2-J-LECP-2Software : PFAT:VGER Product Data Set ID : VG2-J-LECP-4-15MIN Software 'PFAT:VGER' -------------------Software Name : PFAT:VGER Software Type : PIN Software Release Date : N/A Node ID : N/A Cognizant Engineer : N/A Software Access Description : N/A Data Coverage ============= Filename Records Start Stop ------------------------------------------------------------------Volume ID: VG_1502 SECTOR.TAB 64944 1979-07-02T07:35:11.000 1979-08-03T23:30:21.000 SECTOR_SUMMARY.TAB 784 1979-07-02T07:00:00.000 1979-08-03T22:00:00.000

These data are available on-line from the Planetary Data System (PDS) at:

https://pds-ppi.igpp.ucla.edu/data/VG2-J-LECP-4-SUMM-SECTOR-15MIN-V1.1/

Alternate Names

  • VG2-J-LECP-4-SUMM-SECTOR-15MIN-V1.1

Discipline

  • Planetary Science: Fields and Particles

Additional Information

Spacecraft

Experiments

Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. Stamatios M. KrimigisData ProviderApplied Physics Laboratorytom.krimigis@jhuapl.edu
Dr. Barry H. MaukGeneral ContactApplied Physics Laboratory
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